A coaxial cable is a known type of electrical cable that may be used to carry radio frequency (“RF”) signals. Coaxial cables are widely used as transmission lines in cable television networks and/or to provide broadband Internet connectivity. FIG. 1 is a perspective view of a conventional coaxial cable 10 that has been partially cut apart to reveal its internal structure. As shown in FIG. 1, the coaxial cable 10 has a central conductor 12 that is surrounded by a dielectric insulator 14. A tape 16 may be bonded to the outside surface of the dielectric insulator 14. A metallic electrical shield 18, which typically comprises braided shielding wires and, optionally, one or more electrical shielding tapes (not shown in FIG. 1), surrounds the central conductor 12, dielectric insulator 14 and tape 16. Finally, a cable jacket 20 surrounds the electrical shield 18.
A coaxial cable such as cable 10 has two conductors, namely the central conductor 12 and the electrical shield 18. Current travels outward from the source on one of the conductors 12, 18 and returns on the other conductor 12, 18. However, as coaxial cables such as cable 10 are typically used to carry alternating currents, it will be appreciated that the current flow reverses direction on the conductors 12, 18 many times per second. Typically, a conductor that carries high frequency signals such as RF signals acts as an antenna, and thus some of the signal energy is radiated from the conductor, resulting in signal loss or “attenuation.” Coaxial cables, however, are designed to minimize such signal attenuation by positioning the first conductor (central conductor 12) inside the second conductor (electrical shield 18), and by connecting the second conductor 18 to a reference voltage such as an electrical ground reference. As a result of this arrangement, the electromagnetic field of the signal carried by the central conductor 12 is generally trapped in the space inside the electrical shield 18, thereby greatly reducing signal leakage and associated signal attenuation losses.
Typically, each end of a coaxial cable is terminated with a male coaxial connector that may be used to connect the coaxial cable to a female coaxial connector port. The most common type of male and female coaxial connectors are known in the art as “F-style” coaxial connectors. A conventional male F-style coaxial connector is depicted in FIGS. 2-4, and a conventional female F-style coaxial connector port is depicted in FIG. 5. Both of these connectors are described in detail below. Female F-style connector ports are commonly mounted on wall plates in homes and on various devices such as televisions, cable modems, etc. As shown in FIG. 5, a typical female F-style connector port comprises an externally threaded cylindrical housing that includes an aperture on one end thereof that is configured to receive a protruding central conductor of a male F-style coaxial connector. As shown in FIGS. 2-4, a typical male F-style coaxial connector includes an internally-threaded nut which is threaded onto the externally-threaded housing of the female F-style coaxial connector port. A coaxial cable that includes a male coaxial connector on at least one end thereof is referred to herein as a “patch cord.” Jumper cables that are commonly used, for example, to connect a device such as a cable television or a cable modem to a wall outlet are one well known type of patch cord.
FIG. 2 is a perspective view of a conventional male F-style coaxial connector 30. FIG. 3 is a side cross-sectional view of the male F-style coaxial connector 30 of FIG. 2. FIG. 4 illustrates the connector 30 of FIGS. 2-3 after it has been attached to an end of a coaxial cable 10.
As shown in FIGS. 2-4, the connector 30 includes a tubular connector body 32, a compression sleeve 34, a contact post 36 and an internally-threaded nut 38. The contact post 36 includes a pedestal 36′ and a post extending therefrom. In FIG. 2, the compression sleeve 34 is depicted in its “unseated” position in which it may receive a cable that is to be terminated into the connector 30.
When the compression sleeve of connector 30 is in the unseated position, a coaxial cable such as cable 10 may be inserted axially into the compression sleeve 34 and the tubular connector body 32. In particular, the central conductor 12, dielectric insulator 14 and tape 16 (coaxial cable 10 is not depicted in FIGS. 2-3 to more clearly show the structure of the connector 30) are inserted axially into the inside diameter of the contact post 36, while the electrical shield 18, and the cable jacket 24 are inserted so as to circumferentially surround the outer surface of the contact post 36. The outside surface of the contact post 36 may include one or more serrations, teeth, lips or other retention structures 37 (see FIG. 3). Once the cable 10 is inserted into the connector 30 as described above, a compression tool may be used to forcibly axially insert the compression sleeve 34 further into the tubular connector body 32 into its “seated” position (see FIG. 4). The compression sleeve 34 directly decreases the radial gap spacing between the connector body 32 and the contact post 36 so as to radially impart a generally 360-degree circumferential compression force on the electrical shield 18 and the cable jacket 20 that circumferentially surround the outer surface of contact post 36. This compression, in conjunction with the retention structures 37 on the outside surface of the contact post 36, applies a retention force to the coaxial cable 10 that firmly holds the coaxial cable 10 within the connector 30. As shown in FIG. 4, the central conductor 12 of the coaxial cable 10 extends into the internal cavity of the nut 38 to serve as the male protrusion of the connector 30.
As noted above, male F-style coaxial connectors are used to mechanically and electrically attach a coaxial cable such as cable 10 to a female connector port such as, for example, a standard coaxial cable wall outlet or a port on an electronic device such as a cable-ready television set. FIG. 5 is a perspective view of a conventional F-style female connector port 40. As shown in FIG. 5, the female connector port 40 may comprise a cylindrical housing 41 that has a plurality of external threads 42. The distal face 44 of the cylindrical housing 41 includes an aperture 46. A central conductor 48 (barely visible in FIG. 5) runs longitudinally through the center of the female connector port 40. This central conductor 48 is configured to receive the central conductor 12 of a mating male F-style coaxial connector 30. The rotatable nut 38 of a mating male coaxial connector 30 is inserted over, and threaded onto, the female connector port 40 so that the central conductor 12 of the coaxial cable 10 that is attached to the connector 30 is received within the aperture 46, thereby mechanically and electrically connecting coaxial cable 10 to the female connector port 40.